The invention described herein relates generally to improved detonator devices and more particularly to detonator devices which contain only nonprimary explosives. Because of their reduced sensitivity to shock, electrostatic charge, heat, and the like, such devices are far less hazardous than those which contain primary explosives.
In various types of military ordnance and in a great many applications of high explosives in the civil sector, there is a continuing demand for safe, reliable detonators which can be routinely actuated by small amounts of electrical energy.
Detonators employing only nonprimary explosives have been previously developed. One example known in the art as the "flying-plate" detonator is disclosed and claimed in U.S. Pat. No. 3,978,791 which was issued Sept. 7, 1976. In this detonator, low voltage current is passed through a small diameter bridge, heating it and igniting deflagration in a secondary donor explosive. The gas pressure produced by this deflagration causes the central portion of a metal disk to be sheared away and propelled down a hollow bore to impact on a secondary acceptor explosive with sufficient velocity and force to initiate detonation in the acceptor explosive. In this device there is no transition from deflagration to detonation in an explosive train, but rather the energy of the "flying plate" impacting on the acceptor explosive initiates detonation therein.
There are certain problems associated with the use of a "flying plate" in a detonator. In order to achieve proper detonation of the acceptor secondary explosive, U.S. Pat. No. 3,978,791 teaches that the "flying plate" must retain its structural integrity and not disintegrate into small fragments. Moreover, it must be accelerated so as to impact on the acceptor explosive with a velocity of at least one millimeter per microsecond.